Method of manufacturing a molded multilayer article and apparatus therefor

ABSTRACT

Molten polymers are forced into T dies combined to form a multiple T die, the molten polymers are extruded through the T dies in monolayer. The monolayers extruded through the T dies are superposed and laminated outside the multiple T die while the polymers are in a molten or semi-molten state to form a intermediate molten multilayer. The multiple T die is advanced into a space between an open top half mold and a bottom half mold of a compression mold to deliver the intermediate multilayer onto the bottom half mold. The intermediate multilayer is cut to a predetermined length on the bottom half mold, and is processed for compression molding in the compression mold to form a multilayer article. A molding cycle for molding the multilayer article is carried out automatically at a remarkably improved manufacturing efficiency.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method of manufacturing amolded multilayer article and an apparatus therefor. More specifically,the present invention relates to a method and an apparatus which iscapable of efficiently producing molded multilayer article in a widevariety of sizes and shapes by combining a process of laminating aplurality of a extruded molten polymer layer and a process ofcompression molding.

[0003] 2. Description of the Related Art

[0004] Known processes of manufacturing a monolayer article of athermoplastic polymer adapt a combination of an injection moldingprocess and a press forming process, or a combination of an extrusionmolding process and a vacuum forming process for shaping a film or sheetinto a article with a relatively broad width and a complicatedthree-dimensional shape.

[0005] A sheet is formed by extruding a molten polymer through anextrusion die, and successively the sheet is feed to molds forcompression molding process. Therefore, the extrusion die and theassociated parts must be moved toward the molds. Various devices adaptedfor moving an extrusion die along a predetermined path over the bottomhalf mold of an open mold have been disclosed, for example, in JPB No.17931/1982 and JPA No. 137814/1988.

[0006] A stampable sheet molding process applied to processes forproducing that kind of sheet products is one of the known processes. Inthe stampable sheet molding process, a sheet formed by extrusion is cutinto a workpiece with a predetermined size, and the workpiece issoftened by heating and delivered to final molding process on acompression molding machine. Such a processing method comprises steps ofextrusion, forming, cutting process, heating process, and compressionmolding. However, additional electric power consumption is increased forheating process and limited varieties of shape of the products to beprocessed by the compression molding is one of the drawbacks.

[0007] The extrusion die employed in those known techniques has a dieslot opening of a fixed dimension. Therefore the extrusion die can beused only for extruding a sheet of a predetermined fixed width and isnot applicable to extrusion of a sheet with varying width and thickness.

[0008] An apparatus disclosed in JPB No. 25689/1989 is adapted formolding finished sheet products with varying width by extruding a sheetwith varying width, which is feed to compression molding machines.

[0009] This apparatus is capable of changing the sectional shape of asheet which is extruded through a die disposed opposite to thecompression molding machine according to the shape of an finishedproduct.

[0010] The foregoing prior art techniques relate to monolayer articles.One kind of molded articles has a structure of laminated layersconsisting of sheets or films in different in strength, hardness, coloror such. For example, one of molded multilayers articles consists of abase layer, a mid-layer and a skin layer.

[0011] Prior art methods of manufacturing molded multilayer articles ofthe abovementioned kind and apparatus therefor are disclosed in JPB No.2491/1993 and JPA No.24128/1993. In these prior art, a multilayer sheetis formed by co-extruding molten polymers through a multilayer T (slot)die, and the multilayers sheet are fed to molds of a compression moldingmachine for the subsequent compression molding process.

[0012] Since the multilayer sheet is formed in the multilayer T die, itis difficult to control the respective temperatures of the monolayersheets individually. Particularly, it is difficult to hold the mid-layercontaining a foaming agent at a temperature which will not cause thefoaming agent to produce foams until the multilayer sheet is subjectedto a compression molding process because the mid-layer is heated by theadjacent layers of molten polymers and the T die.

[0013] A cutting process for a sheet formed by extruding molten polymerthrough T die is disclosed in JPB No.44124/1985. In this cuttingprocess, the sheet is cut to a length by moving a cutting blade in adirection perpendicular to the width of the sheet at the die slotopening of the T die.

[0014] When the sheet is cut by such a manner that the molten polymerhas a tendency to adhere to part of the T die around the die slotopening, the scorched polymer is liable to adhere to the surface of thesheet, the cutting blade becomes dull due to heating at a hightemperature, and the molten polymer is liable to adhere also to thecutting blade during the sheet cutting process.

[0015] Because the molten polymer is in a state that has a low viscosityand highly adhesive in a sheet cutting process, difficulty in cuttingthe sheet by the cutting blade will be enhanced. Therefore, a cleaningmeans must be disposed near the cutting blade and the cutting bladeneeds relatively frequent cleaning so that the molten polymer may notadhere to the cutting blade kept on standby near the die slot opening ofthe T die.

[0016] Cleaning of the cutting blade increases the molding cycle timeand reduces the efficiency of the manufacturing process greatly. If thecutting blade is not kept satisfactorily clean, the quality of moldingswill be deteriorated.

[0017] The improvement of the efficiency of processes for manufacturingmolded multilayersheet parts of complicated shapes has been a mainproblem that faces manufacturers. Particularly, in a case that amultilayer article consists of component sheets differing from eachother in material, thickness and shape, it is impossible to achieve aseries of processes including a extrusion process, a laminating process,a cutting process and a compression process by single reciprocatingstroke of the T die.

SUMMARY OF THE INVENTION

[0018] Accordingly, it is an object of the present invention to providea molded multilayer article manufacturing method which is capable ofautomatically carrying out a molding cycle including an extrusionprocess of extruding a plurality of monolayers through a plurality of Tdies, a forming process of superposing and laminating the plurality ofmonolayers, and a compression molding process for a finished article ofdesired shape, and of carrying out the molding cycle at a very highmanufacturing efficiency, and to provide a multilayersheet moldingmanufacturing apparatus for carrying out the method.

[0019] A second object of the present invention is to provide a moldedmultilayer article manufacturing method and apparatus capable ofefficiently manufacturing a multilayer article consisting of a pluralityof monolayers differing from each other in width, shape and such.

[0020] A third object of the present invention is to provide a methodand apparatus capable of feeding a plurality of molten monolayersextruded through a plurality of T dies and quickly and smoothly cuttingit to a desired length for a compression molding process to improvemanufacturing efficiency.

[0021] According to one aspect of the present invention, a method formanufacturing a molded multilayer article by molding a multilayer sheetconsisting of a plurality of polymer layers, said method comprises thesteps of: extruding a plurality of monolayers of molten polymers byforcing the molten polymers into a multiple T die combined with aplurality of T dies so that the molten polymers are extrudedrespectively through the T dies; forming an intermediate moltenmultilayer by superposing and laminating the monolayers extruded throughthe T dies outside the multiple T die while the polymers are in a moltenstate or a semi-molten state; feeding the intermediate molten multilayerto a compression mold having the bottom half mold and a top half mold byadvancing the multiple T die into a space between the bottom half moldand the top half mold;

[0022] cutting the intermediate molten multilayer to a predeterminedlength; and molding the intermediate molten multilayer in thecompression mold into a multilayer article of a desired shape.

[0023] According to another aspect of the present invention, anapparatus for manufacturing a molded multilayer article by molding amultilayer sheet, said apparatus comprises: a plastication means forseparately plasticating polymers for forming each of monolayers, andfeeding molten polymers by pressure; a multiple T die combined with aplurality of T dies for extruding the monolayers and jointed to theplastication means; moving means for moving the plastication means andthe multiple T die all together; a laminating means provided with themultiple T die to form a intermediate molten multilayer by superposingand laminating the monolayers extruded in molten or semi-molten state; acutting means provided with the multiple T die for cutting theintermediate molten multilayer in a predetermined length; and acompression molding means provided with a mold for molding theintermediate molten multilayer into a finished multilayer article of adesired shape.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects, features and advantages of thepresent invention will become more apparent from the followingdescription taken in connection with the accompanying drawings, inwhich:

[0025]FIG. 1 is a schematic side view of a molded multilayer articlemanufacturing apparatus in a first embodiment according to the presentinvention;

[0026]FIG. 2 is a schematic plan view of the molded multilayer articlemanufacturing apparatus in the first embodiment shown in FIG. 1;

[0027]FIG. 3 is an enlarged sectional view of an essential part of amultiple T die included in the molded multilayer article manufacturingapparatus in the first embodiment shown in FIG. 1;

[0028]FIG. 4 is a schematic view, similar to FIG. 3, of assistance inexplaining a mode of feeding multilayers extruded through the multiple Tdie of FIG. 3 to a bottom half mold of a compression mold of acompression molding machine;

[0029]FIG. 5 is a typical longitudinal sectional view of an essentialpart of the molded multilayer article manufacturing apparatus in thefirst embodiment shown in FIG. 1;

[0030]FIG. 6 is a schematic sectional view showing an intermediatemultilayers obtained by cutting a multilayers and fed to the bottom halfmold of the compression mold;

[0031]FIG. 7 is a block diagram of a sequential control system for theautomatic sequential control of the molten multilayer articlemanufacturing apparatus in the first embodiment shown in FIG. 1;

[0032] FIGS. 8(a) to 8(e) are perspective views of molded multilayerarticle of different shapes manufactured by the first embodiment shownin FIG. 1;

[0033]FIG. 9 is a schematic view of a die slot opening adjustingmechanism;

[0034]FIG. 10 is a block diagram of an open-loop control system includedin the molded multilayer article manufacturing apparatus in the firstembodiment shown in FIG. 1;

[0035]FIG. 11 is a block diagram of a closed-loop control systemincluded in the molded multilayer article manufacturing apparatus in thefirst embodiment shown in FIG. 1;

[0036]FIG. 12 is a time chart of assistance in explaining the sequentialoperations of mechanisms included in the molded multilayer articlemanufacturing apparatus in the first embodiment shown in FIG. 1;

[0037]FIG. 13 is a schematic sectional view of a sheet cutting mechanismincluded in the molded multilayer article manufacturing apparatus in thefirst embodiment shown in FIG. 1;

[0038]FIG. 14 is a schematic sectional view of the sheet cuttingmechanism of FIG. 13 in a cutting operation;

[0039]FIG. 15 is a schematic side view of assistance in explaining thearrangement of the sheet cutting mechanism of FIG. 13;

[0040]FIG. 16 is a perspective view of assistance in explaining a sheetcutting operation of a cutting blade included in the sheet cuttingmechanism of FIG. 13;

[0041]FIG. 17 is a schematic sectional view of a sheet cutting mechanismfor cutting a monolayer;

[0042]FIG. 18 is a schematic sectional view of a sheet cutting mechanismincluded in a molded multilayer article manufacturing apparatus in asecond embodiment according to the present invention;

[0043]FIG. 19 is a schematic sectional view of the sheet cuttingmechanism of FIG. 18 in a cutting operation;

[0044]FIG. 20 is a schematic plan view of assistance in explaining thearrangement of the sheet cutting mechanism of FIG. 18;

[0045]FIG. 21 is a perspective view of assistance in explaining a sheetcutting operation of a cutting blade included in the sheet cuttingmechanism of FIG. 18;

[0046]FIG. 22 is a schematic sectional view of a sheet cutting mechanismincluded in a molded multilayer article manufacturing apparatus in athird embodiment according to the present invention;

[0047]FIG. 23 is a schematic perspective view of the sheet cuttingmechanism of FIG. 22;

[0048]FIG. 24 is a schematic sectional view of a modification of thesheet cutting mechanism of FIG. 22;

[0049]FIG. 25 is a schematic perspective view of the sheet cuttingmechanism of FIG. 24;

[0050] FIGS. 26(a), 26(b) and 26(c) are schematic sectional views of asheet cutting mechanism included in a molded multilayer articlemanufacturing apparatus in a fourth embodiment according to the presentinvention in different phases of operation;

[0051]FIG. 27 is a schematic plan view of assistance in explaining thearrangement of the sheet cutting mechanism of FIG. 26;

[0052] FIGS. 28 is a schematic sectional view of a sheet cuttingmechanism included in a molded multilayer article manufacturingapparatus in a fifth embodiment according to the present invention; and

[0053]FIG. 29 is a schematic perspective view of the sheet cuttingmechanism of FIG. 28.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] Methods of manufacturing a molded multilayer article andapparatus therefor in accordance with the present invention will bedescribed hereinafter with reference to the accompanying drawings.

1. Molded Multilayer Article Manufacturing Apparatus

[0055] FIGS. 1 to 7 show a molded multilayer article manufacturingapparatus in a first embodiment according to the present invention. Thefirst embodiment will be described as applied to manufacturing a moldedartile with three layers. Numeral 10 represents a plastication means forplasticating polymer material for each of the layers and applyingpressure to molten polymer to force it out. As shown in FIG. 2, aninjection molding machine acting as the plastication means 10 isprovided with three injection units 10 a, 10 b and 10 c disposed in aparallel arrangement. The injection units 10 a, 10 b and 10 c havedelivery nozzles 12 a, 12 b and 12 c, which are connected to T dies 14a, 14 b and 14 c(a slot die is referred to as the T die) respectively.The molten polymer is pushed through the T die 14 a, 14 b and 14 c thatshapes the molten polymer into a molten monolayer, respectively.

[0056] As shown in FIG. 9, the T dies 14 a, 14 b and 14 c are providedwith decides for adjusting slot opening to adjust the widths of themolten monolayer extruded through the slot openings of the T dies 14 a,14 b and 14 c, respectively. The T dies 14 a, 14 b and 14 c areassembled to construct a multiple T die 14. The polymer are formed intothe molten monolayers by the extrusion through the T dies 14 a, 14 b and14 c of the T die 14 in a molten state or a semi-molten state. Thepolymer layers of the molten or semi-molten polymer are laminated toform a intermediate molten multilayer 16.

[0057] The intermediate molten multilayer 16 is cut to a predeterminedlength, and fed to a compression molding machine 18. The compressionmolding machine 18 is provided with a mold consisted of a top half mold24 a and a bottom half mold 24 b, and a mold clamping mechanism to movethe top half mold 24 a vertically relative to the bottom half mold 24 band to close the mold tightly. The intermediate molten multilayer 16 isplaced on the bottom half mold 24 b, and then the top half mold 24 acompresses the intermediate multilayer against the bottom half mold 24 bto shape it into a desired form.

[0058] Referring to FIG. 1, the injection units 10 a, 10 b and 10 c aremounted on a base 19 placed on a bed 17. The base 19 can be horizontallyreciprocated by a base moving mechanism 22 provided with a drive motor(not shown) and rack and pinion mechanism (not shown), which are builtin the bed 17. The multiple T die 14 is reciprocated together with thebase 19 from a standby position indicated by continuous lines in FIG. 1to a space between the open top half mold 24 a and the bottom half mold24 b of the compression molding machine 18. A position of the multiple Tdie 14 indicated by alternate long and a short dash lines in FIG. 1 isthe foremost position of the multiple T die where the feed of theintermediate molten multilayer to the bottom half mold 24 b is started.

[0059] Thus, the multiple T die 14 can be moved together with theinjection units 10 a, 10 b and 10 c into and out of the space betweenthe open top half mold 24 a and the bottom half mold 24 b.

[0060] Refering to FIG. 3, a laminating mechanism 26 is disposed nearthe slot openings of the multiple T die 14 integrally therewith. Thelaminating mechanism 26 forms the intermediate molten multilayer 16 bylaminating molten monolayers 16A, 16B and 16C extruded through the Tdies 14 a, 14 b and 14 c respectively. The laminating mechanism 26 isdisposed upstreams of a cutting mechanism 20 for cutting theintermediate molten multilayer 16 to a predetermined length with respectto a direction in which the intermediate molten multilayer 16 isdelivered. The laminating mechanism 26 is porvided with a pair of niprollers 26 a and 26 b which sandwiches the mid-monolayer 16C between theouter monolayer 16A and 16B in a manner that air may not be trappedbetween each monolayer 16A, 16B and 16C. Cylinder actuators 27 a and 27b are connected to operate the nip rollers 26 a and 26 b. When the niprollers 26 a and 26 b moves toward each other, the monolayers 16A, 16Band 16C are pressed between the nip rollers 26 a and 26 b to form theminto the laminated intermediate molten multilayer 16.

[0061] The laminating mechanism 26 is capable of dealing with alaminating operation for a predetermined intermittent pattern forforming an intermediate molten multilayer consisted of pieces of themonolayers 16A 16B and 16C of different lengths. Multilayer articleshaving such the intermittent patterns and shapes can be manufactured bymoving the nip rollers 26 a and 26 b toward and away from each otheraccording to the pattern.

[0062] The cutting mechanism 20 is disposed below the slot openings ofthe multiple T die 14 to cut off the intermediate molten multilayer 16.The cutting mechanism 20 and the laminating mechanism 26 are combinedwith the multiple T die 14 and are moved together with it. As shown inFIG. 5, the cutting mechanism 20 has a pair of cutting blades disposedon the opposite sides of the intermediate molten multilayer 16 to nip itoff. Any suitable one of various modifications, which will be describedlater, of the cutting mechanism 20 may be employed.

[0063]FIG. 5 is a typical longitudinal sectional view showing anessential part of the multilayer artticle manufacturing apparatus andthe arrangement of limit switches for the positioning of the multiple Tdie 14 and for the sequential control of operations of the componentmechanisms of the apparatus. FIG. 7 is a block diagram for a automaticsequential control system.

[0064] Referring to FIG. 5, a limit switch LS includes contacts 1 to 4disposed on the bed 17. A contact operating member 30 for operating thecontacts 1 to 4 is attached to the base 19 on which the injection units10 a, 10 b and 10 c are mounted. The contact operating member 30 closesand opens the contacts 1 to 4 of the limit switch LS according to theposition of the multiple T die 14 as the base 19 is moved. The contacts1 to 4 of the limit switch LS correspond, respectively, to positions LS1to LS4 on the bottom half mold 24 b of the compression molding machine18. Signals indicating the condition of the contacts 1 to 4 of the limitswitch LS is sent from the base moving mechanism 22 to a sequencer 34.Then the sequencer 34 executes a sequential control program on the basisof the input signals to control the operational sequence of themultilayer article manufacturing apparatus.

[0065] In the first embodiment, when the base 19 moves forward and thecontact 1 of the limit switch LS is closed by the contact operatingmember 30, the slot openings of the multiple T die is located at aposition directly above the position LS1 on the bottom half mold 24 b.When the multiple T die 14 is moved backward, and the contact 2, 3 or 4of the limit switch LS is closed, a end portion of the intermediatemolten multilayer cut by the cutting mechanism 20 corresponds to theposition LS2, LS3 or LS4. When the multiple T die 14 is at a positionshown in FIG. 5, the contact 3 of the limit switch LS is closed. If theintermediate molten multilayer 16 is cut off by the cutting mechanism 20at the moment when the contact 3 of the limit switch LS is closed, thecutting end lie at the position LS4 on the bottom half mold 24 b.

[0066] In FIG. 5, indicated at 31 is an injection cylinder actuator foradvancing screws 11 a, 11 b and 11 c of the injection units 10 a, 10 band 10 c to deliver the molten polymer to the multiple T die 14.

[0067]FIG. 7 shows the sequential control system including the sequencerfor controlling process elements of the multilayer article manufacturingapparatus. The shape patterns of each layers of the multilayer articlecan be specified by operating a setting panel 35. A central processingunit (CPU) 32 executes a sequential control program specifying thesequence of processes to be carried out according to the specified shapepatterns, and gives instructions to the sequencer 34. Then the sequencer34 controls operative sequences of the process elements according to theinstructions given thereto.

[0068] The T dies 14 a, 14 b and 14 c of the multiple T die 14 areprovided with adjusting devices 42 a, 42 b and 42 c, which will bedescribed later, for adjusting the widths of the layers 16A, 16B and 16Cextruded through the slot openings of the T dies 14 a, 14 b and 14 c,respectively. The adjusting devices 42 a, 42 b and 42 c are controlledby the sequencer 34.

[0069] The compression molding machine 18 is provided with a moldexchanging device 36 and a mold heating/cooling device 38 which arecontrolled by the sequencer 34.

[0070] The operations in the multilayer article manufacture will bedescribed hereinafter with reference to FIGS. 5 to 7.

[0071] Referring to FIG. 5, the screws 11 a, 11 b and 11 c of theinjection units 10 a, 10 b and 10 c of the plastication means 10 areadvanced to force the molten polymer through the delivery nozzles 12 a,12 b and 12 c into the T dies 14 a, 14 b and 14 c of the multiple T die14. The molten polymer is formed into the molten monolayers 16A, 16B and16C by extrusion through the T dies 14 a, 14 b and 14 c.

[0072] The multiple T die 14 continues to extrude the monolayer 16A, 16Band 16C, while the injection unit 10 a, 10 b and 10 c together with thebase 19 is advanced to move the multiple T die 14 into the space betweenthe open top half mold 24 a and the bottom half mold 24 b. Themonolayers 16A, 16B and 16C are superposed and laminated between the niprollers 26 a and 26 b disposed below the multiple T die 14 to form theintermediate molten multilayer 16.

[0073] The multiple T die 14 is advanced further into the space betweenthe top half mold 24 a and the bottom half mold 24 b, until the multipleT die 14 arrives at the position directly above the position LS1 wherecontact 1 of the limit switch LS is switched on. Consequently, the endportion of the intermediate molten multilayer 16 hanging from themultiple T die 14 falls upon the position LS1 on the bottom half mold 24b.

[0074] The sequencer 34 gives a instruction to the base moving mechanism22 to retreat the multiple T die 14. While retreating, the intermediatemolten multilayer 16 is extruded continuously through the multiple T die14 so as to be placed onto the bottom half mold 24 b.

[0075] Upon the arrival of the multiple T die 14 at a position directlyabove the position LS3 (FIG. 5), the contact 4 of the limit switch LS isswitched on and an on-signal is given to the sequencer 34. The sequencer34 actuates the cutting mechanism 20 to cut off the intermediate moltenmultilayer 16 to a predetermined length. When the cut end portion of theintermediate molten multilayer 16 is placed onto the position LS4, thedelivery of the intermediate molten multilayer 16 to the bottom halfmold 24 b is completed.

[0076] Thus, laminating process of the monolayers 16A, 16B and 16Cextruded through the multiple T die 14 and the delivery of theintermediate molten multilayer 16 to the bottom half mold 24 b isaccomplished with one motion of the base moving mechanism 22.

[0077] Since the monolayers 16A, 16B and 16C in molten state aresuperposed and cut, the cut edges of the monolayers 16A, 16B and 16C canbe welded together. Therefore, the end portion of the intermediatemolten multilayer 16 can be easily set on the bottom half mold 24 b forthe next compression molding cycle, and the yield rate can be improved.

[0078] In a compression molding process, namely, the last process, thetop half mold 24 a is lowered to compress the intermediate moltenmultilayer 16 between the top half mold 24 a and the bottom half mold 24b to form it into the desired shape as a multilayer article.

[0079] It is preferable to assemble the T dies 14 a, 14 b and 14 c sothat the intermediate molten multilayer 16 with the thickest or heaviestmonolayer 16B as a most below layer is delivered to the bottom half mold24 b as shown in FIG. 4. When the T dies 14 a, 14 b and 14 c areassembled so as to meet the foregoing requirement, it is preferable todisposed the T die 14 b connected to the injection unit 10 b so that thedelivery nozzle 12 b is the shortest among the delivery nozzles 12 a, 12b and 12 c as shown in FIG. 2 to force the molten polymer into the T die14 b at a low pressure loss and to save space.

2. Structural Patterns of Multilayer Articles

[0080] Multilayer articles of various shapes that can be manufactured bythe present invention will be described with reference to FIGS. 8(a) to8(e).

Structure 1

[0081] A multilayer artticle 40 a shown in FIG. 8(a) is a three layerstructure consisting of a first monolayer 16A serving as a skin layer, asecond monolayer 16B serving as a base layer, and a third monolayer 16Cserving as an mid-layer, and the monolayers 16A, 16B and 16C have thesame shape and made of the same thermoplastic polymer, such as apolyolefin.

Structure 2

[0082] A multilayer article 40 b shown in FIG. 8(b) is a three layerstructure consisting of monolayers 16A, 16B and 16C respectively havingdifferent shapes. The monolayers 16A, 16B and 16C have different shapesin respect of the width pattern, respectively. The adjusting devices 42a, 42 b and 42 c included in the T dies 14 a, 14 b and 14 c arecontrolled so as to vary the widths of the monolayers 16A, 16B and 16Caccording to the patterns as shown in FIG. 8(b) to form the multilayerarticle 40 b have layers in different width patterns.

Structure 3

[0083] A multilayer article 40 c is a two layers structure consisting ofmonolayers 16A and 16C serving as a surface layer, and a monolayer 16Bserving as a base layer. The monolayers 16A and 16C having a differentcolor or made of a material different from each other.

Structure 4

[0084] A multilayer article 40 d shown in FIG. 8(d) has a three layersstructure consisting of a monolayer 16A serving as a skin layer, amonolayer 16B serving as a base layer, and a monolayer 16C serving as amid-layer. The length of the monolayer 16A is shorter than those of themonolayer 16B and 16C. While laminating the monolayers 16A, 16B and 16C,only the monolayer 16A is cut to a predetermined shorter length by thecutting mechanism 20, and the feed of the molten polymer by theinjection unit 10 a to the T die 14 a through which extrudes themonolayer 16A is suspended. That processes enable to form the multilayerarticle 40 d partly varying in the number of layers easily.

Structure 5

[0085] A multilayer article 40 e shown in FIG. 8(e) is a three layersstructure consisting of a monolayer 16A serving as a skin layer, amonolayer 16B serving as a base layer, and a monolayer 16C serving as amid-layer made of a foaming polymer. The monolayers 16A, 16B and 16Chave the same shape.

[0086] The polymer material used for forming the mid-layer 16C containsa foaming agent. The injection unit 10 c plasticates the polymermaterial at a relatively lower temperature which does not cause thefoaming agent generate a gas and feed the polymer material to the T die14 c. The temperatures of the molten polymer forming the skin layer 16Aand the base layer 16B are higher than that of the molten polymer forthe mid-layer 16C by temperatures in the range of 50 to 100° C.

[0087] As is obvious from FIGS. 3 and 4, the multiple T die 14 is not anintegrated die which is composed of the T dies 14 a, 14 b and 14 c, butan assembly of the component T dies 14 a, 14 b and 14 c. Therefore, theT die 14 c interposed between the T dies 14 a and 14 b is safe from heatconduction due to the direct contact, and the temperatures of the T dies14 a, 14 b and 14 c can be independently controlled. Since the moltenpolymers extruded through the T dies 14 a, 14 b and 14 c are laminatedoutside below the multiple T die 14, the temperature of the moltenpolymer extruded through the T die 14 c can be maintained at arelatively low temperature that will not cause the foaming agent togenerate a gas. Therefore, the intermediate molten multilayer 16 is fedto the compression molding machine 18 in a state where the molten layer16C is kept unfoamed.

[0088] As shown in FIG. 5, the intermediate molten multilayer 16 iscompressed between the top half mold 24 a and the bottom half mold 24 bto mold it into the desired shape for the finished part. The clampedmold is detached from the compression molding machine 18 and replacedwith another mold by the mold exchanging device 36. The detached mold isheated by the heating/cooling unit 38 at a predetermined temperaturewhere the layer 16C foams.

[0089] Preferably, the mold exchanging device 36 replaces a mold 24A inwhich the molten layer 16C is foaming with an empty mold, becausefoaming process take sufficient time. By that means, the mold 24A can bekept in the foaming process sufficient to foam the layer 16Csatisfactorily. After the completion of foaming of the layer 16C, themold 24A is cooled before the multilayer article 40 e is ejected fromthe mold 24A. Thus, the mid-layer 16C is kept unfoamed while the moltenlayers 16A, 16B and 16C are laminated. And the layer 16C is made to foamduring the compression molding process to improve the moldability withan excellent aesthetic appearance.

[0090] Furthermore, the mold exchanging device 36 enable the compressionmolding machine 18 to start the next molding cycle immediately, so thatthe multilayer article 40 e can be manufactured efficiently.

3. Automatic Width Control Operation for the Width Adjusting Mechanismsin the T Dies

[0091] The automatic control for the width adjusting mechanisms 42 a, 42b and 42 c to manufacture the multilayer article in various shapes willbe described hereinafter.

[0092]FIG. 9 shows the width adjusting mechanism 42 a disposed in the Tdie 14 a. The width adjusting mechanism 42 b and 42 c disposedrespectively in the T dies 14 b and 14 c are the same as the widthadjusting mechanism 42 a shown in FIG. 9 and hence only the widthadjusting mechanism 42 a will be described.

[0093] Referring to FIG. 9, a pair of decides 52 a and 52 b are fittedinto a slot opening 50 of the T die 14 a so as to be movable in thetransverse direction of the molten layer being extruded through the Tdie 14 a. The deckles 52 a and 52 b are moved simultaneously toward oraway from each other to adjust the length of the slot opening 50.

[0094] Each of the decides 52 a and 52 b is driven by a deckle movingmechanism provided with a servomotor 54. Only the decide movingmechanism and the servomotor 54 for moving the decide 52 b is shown inFIG. 9. A drive shaft of the servomotor 54 is coupled to a ball screw 58by a shaft coupling 56. A slider 60 provided with a ball nut isconnected to one end of the decide 52 b and is supported slidably onguide rods 62 a and 62 b. The ball screw 58 is engaged with the ball nutincluded in the slider 60. The servomotor 54 drives the ball screw 58for rotation to move the slider 60 along the guide rods 62 a and 62 b,so that the deckle 52 b is moved linearly along the slot opening 50 ofthe T die 14 a.

[0095] The positions and velocity of the deckles 52 a and 52 b can becontrolled by controlling the servomotors 54. While the molten polymeris being extruded through the slot opening 50, the decides 52 a and 52 bare held at a predetermined position to shape the molten polymer intothe molten layer in a desirable width. Continuous control of thepositions of the deckles 52 a and 52 b while extrusion through the slotopening 50 makes it possible to vary the molten layer in widthcontinuously.

[0096] Methods of controlling the positions and velocity of the deckles52 a and 52 b will be described below.

Open-Loop Control Method

[0097]FIG. 10 shows an open-loop control system for the positionalcontrol of the deckles to form the multilayer article in the shapesshown in FIGS. 8(a) to 8(e).

[0098] As mentioned above with reference to FIG. 5, the respectivepositions of the injection molding machine 10 (injection units 10 a, 10b and 10 c) and the multiple T die 14 (T dies 14 a, 14 b and 14 c) aredetected by any one of the contacts 1 to 4 of the limit switch LS, andthe sequencer 34 controls operation for extruding the molten polymersaccording to the position of the multiple T die 14.

[0099] The CPU 32 produces instructions to be given to the sequencer 34on the basis of the data set by a setting panel 35 regarding to theshape of the multilayer article. The sequencer 34 gives position(velocity) instructions to the servomotors 54 for the open-loop controlof the positions (velocity) of the decides 52 a and 52 b.

[0100] The sequencer 34 controls a flow regulating solenoid valve 39 toregulate the flow rate of a hydraulic fluid supplied to the injectioncylinder 31. The injection cylinder 31 makes the screws 11 a, 11 b and11 c move forward at a predetermined speed to feed the molten polymer ata predetermined delivery rate. By controlling the delivery rate to besubstantially proportional to the change rates at which the widths ofthe molten layers are changed by the control of the positions (speeds)of the decides 52 a and 52 b, only the width of the molten layers eachextruded through the T dies 14 a, 14 b and 14 c can be controlled withthe molten layers kept in a constant thickness.

[0101] In an embodiment in which extruders for continuous extrusion asthe plastication means are employed instead of the injection unit 10,the rotating rate of the screws of the extruders are controlled to varythe delivery rates of the molten polymer.

Closed-Loop Control Method

[0102]FIG. 11 shows a closed-loop control system for the positionalcontrol of the deckles to form the multilayer article in the shapesshown in FIGS. 8(a) to 8(e).

[0103] Program data for varying the widths of the molten layersaccording to the shape of a multilayer article is prepared by using thesetting panel 35. The CPU 32 gives position instruction signal of thedeckles 52 a and 52 b in accordance with the shape of the part throughthe sequencer 34 to the servomotors 54. Consequently the positions(velocities) of the deckles 52 a, 52 b fitted in the T dies 14 a, 14 band 14 c respectively can be continuously adjusted to vary therespective widths of the molten layers during the extrusion.

[0104] The positions and the velocities of the deckles 52 a and 52 b aredetected by encoders 66 connected to the servomotors 54, and theencoders 66 feed back the detection signals to the sequencer 34 for afeedback control operation. Sensors 68 which detect the positions andthe velocities of the screws of the injection units 10 a, 10 b and 10 cfeed back signals to the sequencer 34 for a feedback control operation.The detected positions (velocities) of the decides 52 a and 52 brepresented by the feedback signals are compared with the instructedpositions (velocities) in order to make the deckles 52 a and 52 b followto the instructions. And the sequencer 34 compares the detectedpositions (velocities) of the screws 11 a, 11 b and 11 c with theinstructions to control the flow rate of the hydraulic fluid suppliedthrough the flow regulating valve 39 to the injection cylinder 31. Thus,the delivery rates at which the molten polymers are delivered by theinjection units 10 a, 10 b and 10 c are successively controlled.

[0105] In an embodiment in which extruders for continuous extrusion asthe plastication means are employed instead of the injection unit 10,the rotating rate of the screws of the extruders are controlled to varythe delivery rates of the molten polymer.

4. Example of Sequential Control Program for Multilayer ArtticleManufacturing

[0106] A sequential control program for the automatic manufacture of themultilayer article will be described by way of example with reference toFIG. 12.

[0107] FIGS. 12(b), 12(c) and 12(d) are time sharing charts of asequential control program for a multilayer article shown in FIG. 12(a),showing a series of operations for the deckles 52 a and 52 b, theinjection units 10 a, 10 b and 10 c, the cutting mechanism 20 and thelaminating mechanism 26. In this example, the multilayer articleconsists of monolayers 16A, 16B and 16C.

[0108]FIG. 12(b) shows a time sharing chart for the monolayer 16Ashortest in length. The position (velocity) of the deckles 52 a, 52 b,the plastication operation of the injection unit 10 a, the cuttingoperation of the cutting mechanism 20, and the laminating operations ofthe laminating mechanism 26 in one fabrication cycle are controlled tofollow in the series of sequences given in the time sharing chart inFIG. 12(b).

[0109]FIG. 12(c) shows a time sharing chart for the monolayers 16B and16C of the same length. The position (velocity) of the deckles 52 a, 52b, the plastication operations of the injection unit 10 b and 10 c, thecutting operation of the cutting mechanism 20, and the laminatingoperations of the laminating mechanism 26 in one fabrication cycle arecontrolled to follow in the series of sequences given the time sharingchart in FIG. 12(c).

[0110] Since the monolayer 16A is shorter than the monolayers 16B and16C in length, the operational sequences of the injection unit 10 a andthe deckles 52 a, 52 b are determined so that the extrusion of themonolayer 16A is scheduled to suspend during the continuous extrusion ofthe monolayers 16B and 16C. While the monolayers 16A, 16B and 16C arelaminated together, the layer 16A exclusive of layers 16B and 16C is cutoff to a predetermined length upon the suspension of the extrusionthereof. As for the rest layers, the monolayers 16B and 16C are extrudedcontinuously up to the completion of extrusion when the monolayers 16Band 16C are cut off to a predetermined length longer that that of thelayers 16A.

[0111] It is noted that the monolayers 16A, 16B and 16C which areuniform in thickness are formed during the extrusion. For that purpose,the decrease rates of the feed of the molten polymer from the injectionunits 10 a, 10 b and 10 c correspond to the reducing rates at which thedeckles 52 a and 52 b regulate the slot opening lengths of the T dies 14a, 14 b and 14 c to narrow the monolayers 16A, 16B and 16C.

[0112]FIG. 12(d) shows a time sharing chart for the multilayer articleof which the monolayer 16C is not uniform in thickness. The deliveryrate at which the injection unit 10 c delivers the molten polymer toextrude the layer 16C is regulated in a manner as shown in FIG. 12(d).

5. Modifications of the Cutting Mechanism

[0113] Modifications of the cutting mechanism will be describedhereinafter.

Cutting Mechanism in First Modification

[0114]FIG. 13 shows a cutting mechanism 100 for cutting the intermediatemolten layer to provide an given length, and FIG. 14 shows the cuttingmechanism 100 in operation.

[0115] The cutting mechanism 100 is disposed downstream of thelaminating mechanism 26 with respect to a feed direction. The cuttingmechanism 100 is provided with a pair of pad members 110 disposedopposite to, each other to press the intermediate molten multilayer 16therebetween. A opposite end surface of each pad member 110 has aspherical surface adaptable for introducing the intermediate moltenmultilayer 16 in contact with it. In this embodiment, each pad member110 is divided into a pair of half pads 110 a and 110 b disposed oneover the other symmetrically with a narrow space 120 formedtherebetween. The pad members 110 each comprising the half pads 110 aand 110 b are connected to diving devices 112, such as hydrauliccylinder.

[0116] Preferably, the spherical surfaces of the pad members 110 to bebrought into contact with the intermediate molten multilayer 16 arecoated with anti-adhesive coatings, respectively, to prevent the moltenpolymer from adhering to the surfaces of the pad members 110. Passages116 as a cooling means through which a coolant is circulated areprovided in the body of the pad membes 110 to cool the heated portion ofthe pad members 110 in contact with the intermediate molten multilayer16.

[0117] The pad members 110 are provided with air passages 118, as a airblowing means, open into the spherical surfaces thereof to blowcompressed air toward the surface of the intermediate molten multilayer16 in order to facilitate the removal from the surfaces of the padmembers 110. The space 120 is confined between the opposite walls of thehalf pads 110 a and 110 b. The spherical surfaces of the half pads 110 aand 110 b are formed so as to protrude toward the intermediate moltenmultilayer 16, and the space 120 is located between the walls whichintersect the top contact surface of the half pads 10 a and 110 b.Either of the pad members 110 is provided with a cutting blade 122disposed in the space 120 between the half pads 110 a, and the cuttingblade can sticks out from the spherical surface of the half pads towardthe intermediate multilayer 16. The cutting blade 122 has a cutting edge122 a and is positioned so that the cutting edge 122 a projects slightlyfrom the spherical surfaces of the half pads 110 a and 110 b. Thecutting blade 122 is connected to a cutter running device 124 whichmoves the cutting blade 122 in the transverse direction of theintermediate molten multilayer 16 to cut it of to a given length.

[0118]FIG. 15 shows the cutter running device 124 in more detail. Thecutting blade 122 is attached to a linear actuator 128 which movesslidably on a guide bar 126 disposed parallel to the transversedirection of the intermediate molten multilayer 16.

[0119] The function of the cutting mechanism 100 will be describedbelow.

[0120] While the molten monolayers 16A, 16B and 16C are extruded throughthe T dies 14 a, 14 b and 14 c of the multiple T die 14, the nip rollers26 a and 26 b of the laminating mechanism 26 laminate them together toform the intermediate molten multilayer 16 by nipping the monolayers16A, 16B and 16C therebetween. The laminated multilayer 16 travelsdownwardly through the space between the pad members 110 of the cuttingmechanism 100.

[0121] When the actuators 112 are actuated to advance the pad members110, the intermediate molten multilayer 16 is held between the padmembers 110 at a position of 30 to 100 mm below the slot openings of theT dies 14 a, 14 b and 14 c as shown in FIG. 14.

[0122] Although the intermediate molten multilayer 16 is in the themolten or semi-molten state as a whole, a small portion thereof incontact with the pad member 110 may be cooled by the cooling effect ofthe coolant flowing through the passages 116. A shaded part shown inFIG. 16 is the cooled portion of the intermediate molten multilayer 16.The cutting blade 122 is disposed so as to be opposite closely to thecooled portion of the intermediate molten multilayer 16. When the cooledportion of the intermediate molten multilayer 16 is solidified into astate sufficient to cut it off easely, the cutter running device 124commence the cutting blade to move. Consequently, the cutting blade 122,which has been on standby, travels transversely to cut off theintermediate molten multilayer 16 to a predetermined length.

[0123] According to the cutting mechanism 100, only the cooled portionof the intermediate molten multilayer 16, including a cutting line, iscooled to semi-solid stated so that the cooled portion 16 can be easilycut along the cutting line. Therefore, the intermediate moltenmultilayer 16 can be quickly and smoothly cut without remaining theadhesion of the molten polymer to the cutting edge 122 a of the cuttingblade 122. As the cut edges of the monolayers 16A, 16B and 16C can besecurely adhered to each other, the leading edge of the intermediatemolten multilayer 16 can be easily set on the molds for the nextcompression molding cycle.

[0124] During the cutting process, the molten intermediate multilayer 16is cut with the cutting blade 122 while the same are pressed between thepresser pads 110, air may not be entered into clearances between thelaminated monolayers 16A, 16B and 16C.

[0125] When retracting the pad member 110 by the driving actuator 112after the intermediate molten multilayer 16 has been cut, compressed airis jetted through the air passages 118 against the intermediate moltenmultilayer 16. Air blowing at the start of retraction of the pad member110 enables the intermediate molten multilayer 16 to peel off from thesurfaces of the pad member 110. Therefore, it is possible to avoid thefirm adhesion of the intermediate molten multilayer 16 to the surfacesof the pad member 110.

[0126] As for a shape of the half pads 110 a and 110 b of the pad member110 having cooling capability of the cutting mechanism 100, a pair ofhalf pads which has a shape of a roller may be used.

[0127]FIG. 17 shows a cutting mechanism 106 which is applied to cuttinga monolayer 102.

[0128] As shown in FIG. 17, the monolayer 102 extruded through a T die104 is cut by the cutting mechanism 106. Thus, the monolayer 102 can beeasily and smoothly cut by the cutting mechanism 106 of the sameconstruction as the cutting mechanism 100 of FIG. 13.

Cutting Mechanism in Second Modification

[0129]FIGS. 18 and 19 show a second modification of the cuttingmechanism 100 of FIG. 13. A cutting mechanism 140 is provided with apair of pad members 110 which ate the same as those of FIG. 13. Theintermediate molten multilayer 16 is held between the pad members 110when the same is cut. In FIGS. 18 and 19, parts like or corresponding tothose of the cutting mechanism 100 of FIG. 13 are designated by the samereference characters and the description thereof will be omitted.

[0130] In the cutting mechanism 140, a metal thin plate 142 for use as acutting blade is disposed in the space 120 between the half pads 110 aand 110 b of one of the pad members 110. The metal thin plate 142 has alength greater than the width of the intermediate molten multilayer 16.The metal thin plate 142 is held in the space 120 so as to be projectedfrom the surface of the pad member 110 which is brought into contactwith the intermediate molten multilayer 16. As shown in FIG. 20, themetal thin plate 142 is held at its opposite ends on holding members 144which are connected to actuators 146 (cutter operating means), such ashydraulic cylinders. The actuators 146 advance the metal thin plate 142in the space 120 toward the intermediate molten multilayer 16 so thatthe cutting edge of the metal thin plate 142 projects from the surfaceof the pad member 110.

[0131] A metal wire, such as a piano wire, may be used instead of themetal thin plate 142 for cutting the intermediate molten multilayer 16.The intermediate molten multilayer 16 can be easily cut with the metalthin plate 142 or a metal wire being heated by a heater built in the padmember 110. It is effective to use, as the metal wire, a nichrome wireor the like which generates heat when electric power is applied.

[0132] The operation of the cutting mechanism 140 will be describedbelow. When the monolayers 16A, 16B and 16C are extruded through the Tdies 14 a, 14 b and 14 c of the multiple T die 14, the monolayers 16A,16B and 16C are laminated between the nip rollers 26 a and 26 b of thelaminating mechanism 26 to form the intermediate molten multilayer 16.The intermediate molten multilayer 16 travels through the space betweenthe pad members 110 of the cutting mechanism 140.

[0133] The intermediate molten multilayer 16 is held between the padmembers 110 at a position about 30 to 100 mm below the die openings ofthe multiple T die 14 as shown in FIG. 19.

[0134] Then, the actuators 146 are actuated to advance the metal thinplate 142 which is kept opposite to a surface of the intermediate moltenmultilayer 16. The metal thin plate 142 is pressed against theintermediate molten multilayer 16 as shown in FIG. 21 to cut it tolength by shearing.

[0135] During the cutting operation of the cutting mechanism 140, theintermediate molten multilayer 16 is held between the pad members 110 sothat air may not be trapped between the laminated molten monolayers 16A,16B and 16C.

[0136] The intermediate molten multilayer 16 can be more easily cut byusing the heated metal thin plate 142 which is pressed against theintermediate molten multilayer 16.

[0137] The actuators 146 retracts the metal thin plate 142 on completionof cutting operation, and the driving devices 112 retracts the padmembers 110. When retracting the pad members 110, compressed air isjetted through the air passages 118 against the intermediate moltenmultilayer 16. Air blowing at the start of retraction of the pad membersenables the intermediate molten multilayer 16 to peel off from thesurface of the pad members 110. Therefore, it is possible to avoid thefirm adhesion of the intermediate molten multilayer 16 to the surfacesof the pad members 110.

[0138] As for a shape of the half pads 110 a and 110 b of the pad member110 having cooling capability of the cutting mechanism 100, a pair ofhalf pads which has a shape of a roller may be used.

[0139] It is noted that the cutting mechanism 140 can be applied to aprocess for cutting a monolayer.

Cutting Mechanism in Third Modification

[0140]FIG. 22 shows a cutting mechanism 150 in a third modification.

[0141] The cutting mechanism 150 according to the third modificationdiffers from the cutting mechanisms 100 and 140 both in disposition andconfiguration. The cutting mechanism 150 is capable of cutting themonolayers 16A, 16B and 16C at positions immediately below the dieopenings of the T dies 14 a, 14 b and 14 c of the multiple T die 14before the monolayers 16A, 16B and 16C are laminated. Therefore, thelaminating mechanism 26 is disposed below the cutting mechanism 150 withrespect to the traveling direction of the intermediate molten multilayer16.

[0142] The cutting mechanism 150 is provided with a metal wire 152,preferably, a piano wire, as a cutting means. The metal wire 152 isextended in contact with or close to exits 15 a, 15 b and 15 c of slotopenings the T dies 14 a, 14 b and 14 c through which the monolayers16A, 16B and 16C are extruded. The metal wire 152 is extended by fourguide bars 156 a, 156 b, 156 c and 156 d so as to be in contact with theexits 15 a, 15 b and 15 c of the slot openings of the T dies 14 a, 14 band 14 c. The metal wire 152 is extended by the four guide bars 156 a,156 b, 156 c and 156 d in a plane perpendicular to the width of themonolayers 16A, 16B and 16C.

[0143] As shown in FIG. 23, the guide bars 156 a, 156 b, 156 c and 156 dare held on a frame 154. In FIG. 23, only the T die 14 a of the multipleT die 14 is shown for simplicity. The metal wire 152 is extended betweena pair of reels 160 respectively driven for rotation by drive motors158. One of the pair of reels 160 is a feed reel for feeding the metalwire 152 and the other is a take-up reel for taking up the metal wire152. A predetermined length of the metal wire 152 is fed out from thefeed reel 160 and is taken up by the takeup reel 160 for every moldingcycle to take up a used section of the metal wire 152 and to feed a newsection of the metal wire 152 for the next molding cycle.

[0144] A metal wire moving mechanism for moving the metal wire 152extended between the reels 160 along the width of the monolayers 16A,16B and 16C will be described below.

[0145] The frame 154, the drive motors 158 and the reels 160 are mountedon a slide block 164 which is supported for sliding along the width ofthe monolayers 16A, 16B and 16C on guide rails 162. In thismodification, the slide block 164 is a rodless cylinder.

[0146] The metal wire 152 is preferably heated beforehand by a suitableheating means so that the intermediate molten multilayer 16 will beeasily cut thereby. And it is effective to employ a Nichrome wire forthe metal wire 152 which generates heat when electrical power isapplied.

[0147] The action of the cutting mechanism 150 will be described inconnection with a cutting method. The monolayers 16A, 16B and 16C areextruded through the T dies 14 a, 14 b and 14 c of the multiple T die14. The slide block 164 kept on standby near one side end of themonolayers 16A, 16B and 16C stats sliding movement along the guide rails162. The metal wire 152 move along the width of the monolayers 16A, 16Band 16C in contact with the exits 15 a, 15 b and 15 c of the slotopenings of the T dies 14 a, 14 b and 14 c. Consequently, the monolayers16A, 16B and 16C are cut to a predetermined length simultaneously at thedie openings of the T dies 14 a, 14 b and 14 c. Thus, the remains ofmonolayers 16A, 16B and. 16C will not be left on the exit 15 a, 15 b and15 c of the slot openings of the T dies 14 a, 14 b and 14 c because theparts of the monolayers 16A, 16B and 16C continuous with the exits 15 a,15 b and 15 c of the slot openings of the T dies 14 a, 14 b and 14 c arecut with the metal wire 152. After cutting the monolayers 16A, 16B and16C, a section of the metal wire 152 used for cutting them is taken upon the take-up reel 160 and a new section of the metal wire 152 isextended for the next cutting cycle. Thus, the monolayers 16A, 16B and16C can be smoothly cut in the next cutting cycle with the new sectionof the metal wire 152 which is not caked with the molten polymer.

[0148] The pieces of the cut off monolayers 16A, 16B and 16C are nippedbetween the nip rollers 26 a and 26 b for lamination to provide anintermediate molten multilayer 16. The intermediate molten multilayer 16is delivered to the bottom half mold 24 b of the compression moldingmachine 18.

[0149]FIGS. 24 and 25 shows a cutting mechanism similar in constructionto the cutting mechanism 150. The cutting mechanism shown in FIGS. 24and 25 employs a metal thin plate 170 instead of the metal wire 152. Asshown in FIG. 24, the metal thin plate 170 is bent and shaped so as tobe in contact simultaneously with the end surfaces 15 a, 15 b and 15 cof the T dies 14 a, 14 b and 14 c in which the die openings thereofopen. In FIG. 25, only the T die 14 a of the multiple T die 14 is shownfor simplicity. The metal thin plate 170 is held on the frame 154capable of moving along the width of the monolayers 16A, 16B and 16C. InFIG. 25, parts like or corresponding to those shown in FIG. 23 aredesignated by the same reference characters and the description thereofwill be omitted.

Cutting Process and Cutting Mechanism in Fourth Modification

[0150] FIGS. 26(a), 26(b) and 26(c) shows different phases of a cuttingprocess for the intermediate molten multilayer 16 which is differentfrom the cutting process of the foregoing embodiments. This cuttingprocess does not use any cutting means. Alternatively, a piece of theintermediate molten multilayer 16 is pulled off by using the nip rollers182 a and 182 b of a laminating mechanism 182 so that a part of themonolayers 16A, 16B and 16C near the die openings of the T dies 14 a, 14b and 14 c is torn off.

[0151] The laminating mechanism 182 for laminating the monolayers 16A,16B and 16C extruded through the T dies 14 a, 14 b and 14 c of themultiple T die 14 to form the intermediate molten multilayer 16 isdisposed below the multiple T die 14.

[0152] The laminating mechanism 182 serves also so as a pulling andcutting means for pulling the intermediate molten multilayer 16 andtearing it off at the die openings of the T dies 14 a, 14 b and 14 c.

[0153] Referring to FIGS. 26(a), 26(b) and 26(c), the pair of niprollers 182 a and 182 b are disposed opposite to each other near the dieopenings of the T dies 14 a, 14 b and 14 c. The monolayers 16A, 16B and16C extruded through the T dies 14 a, 14 b and 14 c are nipped betweenthe nip rollers 182 a and 182 b so that any air may not be trappedbetween the laminated layers to form the intermediate molten multilayer16. The nip rollers 182 a and 182 b, similarly to those of the foregoingembodiments, move together with the multiple T die 14.

[0154] Referring to FIG. 27 showing the laminating mechanism 182,support shafts 184 a and 184 b projecting from the opposite ends of thepair of nip rollers 182 a and 182 b are supported for rotation inbearings 186, respectively. Driven pulleys 188 a and 188 b are mountedon the support shafts 184 a and 184 b, respectively, and drive pulleys192 a and 192 b are mounted on the output shafts of drive motors 190 aand 190 b at positions opposite the driven pulleys 188 a and 188 b,respectively. Synchronous belts 194 a and 194 b are wound around thedriven pulley 188 a and the drive pulley 192 a, and around the drivenpulley 188 b and the drive pulley 192 b, respectively. A actuators 196,such as pneumatic cylinder actuators, are connected properly to thesupport shafts 184 a and 184 b to move the opposite nip rollers 182 aand 182 b toward and away from each other.

[0155] Operations of the multiple T die 14, and the nip rollers 182 aand 182 b during a laminating process and a cutting process will bedescribed hereinafter.

[0156] As shown in FIG. 26(a), the monolayers 16A, 16B and 16C areextruded through the T dies 14 a, 14 b and 14 c while the multiple T die14 is being advanced. Upon the detection of the leading edges of themonolayers 16A, 16B and 16C which past the space between the nip rollers182 a and 182 b by a sensor, not shown, the actuators 196 move the niprollers 182 a and 182 b toward each other. The monolayers 16A, 16B and16C are compressed between the nip rollers 182 a and 182 b so that theintermediate molten multilayer 16 is formed.

[0157] The multiple T die 14 is advanced to a position corresponding tothe front ends of the mold 24 a, 24 b of the compression molding machine18 as shown in FIG. 26(a). The drive motors 190 a and 190 b drives thenip rollers 182 a and 182 b for rotation in the directions of thearrows, respectively. Consequently, the leading edge of the intermediatemolten multilayer 16 reaches one end of the bottom half mold 24 b. Uponthe detection of the arrival of the leading edge of the intermediatemolten multilayer 16 by a suitable sensor, not shown, a holding member200 included in the mold changing device 36 is operated to hold a endportion of the intermediate molten multilayer 16 fixedly on one end ofthe bottom half mold 24 b.

[0158] Subsequently, as shown in FIG. 26(b), the multiple T die 14 ismoved backward together with the laminating mechanism 182. The niprollers 182 a and 182 b are rotated at a rotating rate corresponding tothe moving rate of the multiple T die 14 in order that a laminating rateat which the intermediate molten multilayer 16 is delivered coincideswith a feed rate at which the multilayer 16 is fed onto the bottom halfmold 24 b.

[0159] As shown in FIGS. 26(c), upon the arrival of the multiple T die14 at a position at a short distance from a position corresponding tothe back ends of the mold 24 a, 24 b, the extrusion of the moltenpolymers through the T dies 14 a, 14 b and 14 c of the multiple T die 14is suspended and, at the same time, the rotation of the nip rollers 182a and 182 b holding the intermediate molten multilayer 16 therebetweenis stopped. Then, the rotation of the nip rollers 182 a and 182 b isresumed at the rotating rate for delivering the intermediate moltenmultilayer 16 or at a rotating rate suitable for tearing it off.Consequently, That makes it possible to tear off monolayers 16A, 16B and16C simultaneously at the die openings of the T dies 14 a, 14 b and 14c. The cut edges of the monolayers 16A, 16B and 16C are welded together.After the monolayers 16A, 16B and 16C has been cut, the rotation of thenip rollers 182 a and 182 b is suspended, and the nip rollers 182 a and182 b are moved away from each other. The multiple T die 14 retreatsbeyond the back ends of the mold 24 a, 24 b to its standby position.Meanwhile, the compression molding machine 18 operates for compressionmolding to form the intermediate molten multilayers 16 into a moldedmultilayer article.

[0160] Preferably, the surface of the nip rollers 182 a and 182 b arecoated with anti-adhesive coatings to avoid the adhesion of the moltenpolymers. Preferably, the nip rollers 182 a and 182 b are internallyprovided with temperature control means including coolant passages, notshown, to keep the nip rollers 182 a and 182 b at a predeterminedtemperature while the intermediate molten multilayer 16 is held betweenthe nip rollers 182 a and 182 b. Scrapers 202 a and 202 b may bedisposed in combination with the nip rollers 182 a and 182 b as shown inFIG. 26(b) or blowing means may be combined with the nip rollers 182 aand 182 b to ensure the separation of the intermediate molten multilayer16 from the nip rollers 182 a and 182 b.

[0161] Thus, the monolayers 16A, 16B and 16C extruded through the T dies14 a, 14 b and 14 c of the multiple T die 14 can be laminated bycompressing the same between the nip rollers 182 a and 182 b to form theintermediate molten multilayer 16. Since the nip rollers 182 a and 182 bpulls monolayers 16A, 16B and 16C tear them off at the die openings ofthe T dies 14 a, 14 b and 14 c, any air may not be trapped between thelaminated monolayers 16A, 16B and 16C. Accordingly, the intermediatemolten multilayer 16 properly laminated can be smoothly delivered to themold of the compression molding machine 18.

Cutting Mechanism in Fifth Modification

[0162]FIGS. 28 and 29 show a cutting mechanism 210 in a fifthmodification.

[0163] The cutting mechanism 210 have basically a similar function tothat of the cutting mechanism 150 in the third modification which iscapable to cutting the monolayers 16A, 16B and 16C at the die openingsof the T dies 14 a, 14 b and 14 c of the multiple T die 14 before themonolayers 16A, 16B and 16C are laminated.

[0164] Referring to FIG. 28, cutting members 214 a, 214 b and 214 c areheld on a bracket 212 which is attached to an front end of a swing plate216. The swing plate 216 is supported for swinging by a support shaft218 on brackets 220.

[0165] The swing plate 216 is turned to bring the cutting members 214 a,214 b and 214 c into contact with or to separate the same from the exits15 a, 15 b and 15 c of the slot openings of the T dies 14 a, 14 b and 14c in which the die openings open. The swing plate 216 is forced by aspring 222 to bring the cutting members 214 a, 214 b and 214 c intocontact with the end surfaces 15 a, 15 b and 15 c of the T dies 14 a, 14b and 14 c, respectively.

[0166] The cutting members 214 a, 214 b and 214 c, the bracket 212, theswing plate 216, the support shaft 218 and the brackets 220 constitute acutting unit. A cutter moving mechanism for moving the cutting unit isshown in FIG. 29, in which only the T die 14 a of the multiple T die 14is shown for simplicity.

[0167] The brackets 220 of the cutting unit is attached to a slide block226 supported for sliding on guide rails 224 extended in parallel to thewidth of the monolayers 16A, 16B and 16C. In this modification, arodless cylinder unit is applicable to the the slide block 226.

[0168] An eccentric guide bar 228 is extended with its geometric centeraxis in parallel to the guide rails 224. The eccentric guide bar 228 isprovided in its circumference with a first cam groove 230 a and a secondcam groove 230 b extending in the longitudinal direction. A cam follower232 fixed to the swing plate 216 is in engagement with the first camgroove 230 a as shown in FIG. 28.

[0169] In FIG. 29, the slide block 226 is at its standby position. Whenthe slide block 226 is moved forward for a cutting stroke to cut themonolayers 16A, 16B and 16C, the cam follower 232 moves along the firstcam groove 230 a. When the slide block 226 is moved backward for areturn stroke after the monolayers 16A, 16B and 16C have been cut, thecam follower 232 moves along the second cam groove 230 b.

[0170] Since the cam follower 232 moves along the first cam groove 230 aand the second cam groove 230 b, the eccentric guide roller 228 isturned through an angle of 90 degrees by every travel of the slide block226. As is obvious from FIG. 28, the shaft of the eccentric guide roller228 is displaced by a predetermined eccentricity t from the geometriccenter of the eccentric guide bar 228 so that the second cam groove 230b is included in a plane including a radius longer than a radiusincluded in a plane including the first cam groove 230 a.

[0171] The action of the cutting mechanism 210 will be described inconnection with a cutting method.

[0172] The monolayers 16A, 16B and 16C are extruded through the T dies14 a, 14 b and 14 c of the multiple T die 14. The slide block 226 startsoff on a sliding travel from the standby position along the guide rails224. At this stage, the eccentric guide bar 228 is at an angularposition shown in FIG. 28. As the slide block 226 moves forward for acutting stroke, the cam follower 232 moves along the first cam groove230 a. Therefore, the cutting members 214 a, 214 b and 214 c held on thebracket 212 attached to the end part of the swing plate 216 move incontact with the exits 15 a, 15 b and 15 c of the slot openings of the Tdies 14 a, 14 b and 14 c along the width of the monolayer 16A, 16B and16C. Consequently, the monolayers 16A, 16B and 16C are cut offsimultaneously at the die openings of the T dies 14 a, 14 b and 14 c.Thus, the remains of monolayers 16A, 16B and 16C will not be left on theexits 15 a, 15 b and 15 c of the slot openings of the T dies 14 a, 14 band 14 c.

[0173] In a final stage of the cutting operation, the slide block 226reaches the front end of the cutting stroke, and the cam follower 232 isforced to move from the first cam groove 230 a to the second cam groove230 b and, consequently, the eccentric guide bar 228 is turnedcounterclockwise, as viewed in FIG. 28, through an angle of 90.

[0174] Since the shaft of the eccentric guide bar 228 is displaced fromthe geometric center of the guide bar 228 by the predeterminedeccentricity ε, the swing plate 216 is turned slightly counterclockwise,as viewed in FIG. 28, through the cam follower 232. Consequently, thecutting members 214 a, 214 b and 214 c shift its position so as to beapart from the exits 15 a, 15 b and 15 c of the slot openings of the Tdies 14 a, 14 b and 14 c.

[0175] Then, the slide block 226 is moved backward for return stroke tothe standby position with the cam follower 232 being engaged with thesecond cam groove 230 b. The cutting members 214 a, 214 b and 214 cmaintains a position apart from the exits 15 a, 15 b and 15 c of theslot openings of the T dies 14 a, 14 b and 14 c. Therefore, the moltenpolymers oozing through the die openings of the T dies 14 a, 14 b and 14c will not adhere to the cutting members 214 a, 214 b and 214 c, and themonolayers 16A, 16B and 16C can be smoothly cut with the cutting members214 a, 214 b and 214 c free from adherent polymers in the next cuttingcycle.

[0176] The monolayers 16A, 16B and 16C thus cut off are compressed forlamination between the nip rollers 26 a and 26 b of the laminatingmechanism 26 to shape them into an intermediate molten multilayer 16,which is delivered onto the bottom half mold 24 b of the compressionmolding machine 18.

[0177] Although the invention has been described in its preferred formswith a certain degree of particularity, various changes and variationsmay be made in the design thereof without departing from the scope andspirit of the invention.

[0178] For example, the molded multilayer article manufacturingapparatus may be provided, instead of the injection molding unit as aplastification means, with an extruder provided with plungers andcapable of intermittently extruding molten polymers like the injectionmolding machine.

[0179] The molded multilayer article manufacturing apparatus may beprovided with a guide means including guide rails disposed on a fixedplaten mounted with the bottom half mold so as to extend over the bottomhalf mold to guide the multiple T die, the laminating mechanism and thecutting mechanism for simultaneous movement toward and away from themold of the compression molding machine. The guide means ensures thestable, reliable movement of the multiple T die toward and away from themold in synchronism with the operation of the injection molding machine.Stable molding operation can be achieved even if the heavy combinationof the multiple T die and the laminating mechanism is supported on thedelivery nozzles of the injection molding machine in a cantileverfashion.

What is claimed is:
 1. A method for manufacturing a molded multilayerarticle by molding a multilayer sheet consisting of a plurality oflaminated polymer layers, said method comprising the steps of: extrudinga plurality of monolayers of molten polymers by forcing the moltenpolymers into a multiple T die combined with a plurality of T dies sothat the molten polymers are extruded respectively through the T dies;forming an intermediate molten multilayer by superposing and laminatingthe monolayers extruded through the T dies outside the multiple T diewhile the polymers are in a molten state or a semi-molten state; andmolding the intermediate molten multilayer by using a compression moldinto a multilayer article of a desired shape.
 2. A method formanufacturing a molded multilayer article by molding a multilayer sheetconsisting of a plurality of polymer layers, said method comprising thesteps of: extruding a plurality of monolayers of molten polymers byforcing the molten polymers into a multiple T die combined with aplurality of T dies so that the molten polymers are extrudedrespectively through the T dies; forming an intermediate moltenmultilayer by superposing and laminating the monolayers extruded throughthe T dies outside the multiple T die while the polymers are in a moltenstate or a semi-molten state; feeding the intermediate molten multilayerto a compression mold having the bottom half mold and a top half mold byadvancing the multiple T die into a space between the bottom half moldand the top half mold; cutting the intermediate molten multilayer to apredetermined length; and molding the intermediate molten multilayer inthe compression mold into a multilayer article of a desired shape. 3.The molded multilayer article manufacturing method according to claim 2,wherein the monolayers extruded through the T dies of the multiple T dieinclude a first monolayer of a molten polymer serving as a skin layer, asecond monolayer of a molten polymer serving as a base layer, and atleast one third monolayer of a molten polymer serving as a mid-layersandwiched between the skin layer and the base layer.
 4. The moldedmultilayer article manufacturing method according to claim 3, whereinthe first, the second and the third monolayers are of the same moltenthermoplastic polymer.
 5. The molded multilayer article moldingmanufacturing method according to claim 3, wherein the temperature ofthe molten polymer forced into the T die for extruding the thirdmonolayer is lower than those of the molten polymers forced into the Tdies respectively for extruding the first and the second monolayer. 6.The molded multilayer article manufacturing method according to claim 5,wherein the third monolayer is formed of a molten unfoamed polymercontaining a foaming agent.
 7. The molded multilayer articlemanufacturing method according to claim 5, wherein the thermoplasticpolymer is a polyolefin.
 8. The molded multilayer article manufacturingmethod according to claim 3, wherein each of the monolayer is extrudedthrough the corresponding T die with a predetermined pattern of varyingwidth.
 9. The molded multilayer article manufacturing method accordingto claim 8, wherein the monolayer have different patterns of varyingwidth, respectively.
 10. The molded multilayer article manufacturingmethod according to claim 2, wherein the monolayers are laminated nearthe die slot openings of the T dies so that the monolayer serving as themid-layer is sandwiched between the monolayers respectively serving asthe base layers.
 11. The molded multilayer article manufacturing methodaccording to claim 2, wherein the intermediate molten multilayer isdelivered to the compression mold by cutting it into a predeterminedlength at a position between an open top half mold and a bottom halfmold of the compression mold.
 12. The molded multilayer articlemanufacturing method according to claim 2, wherein the intermediatemolten multilayer is cut at a position below the die slot openings ofthe T dies of the multiple T die with respect to a direction in whichthe monolayers are extruded.
 13. The molded multilayer articlemanufacturing method according to claim 2, wherein the intermediatemolten multilayer is cut in a plane including an exit of a slot openingof the respective T dies.
 14. The molded multilayer articlemanufacturing method according to claim 12, wherein a cutting processfor cutting the intermediate molten multilayer comprises the steps of:disposing a pair of pad members at a position below the die slotopenings of the T dies of the multiple T die; holding the intermediatemolten multilayer between the pair of pad members; cooling a portion ofthe intermediate molten multilayer held between the pair of pad members;and cutting the intermediate molten multilayer along the cooled portionthereof.
 15. The molded multilayer article manufacturing methodaccording to claim 12, wherein a cutting process for cutting theintermediate molten multilayer comprises the steps of: preparing andheating a cutting means; disposing a pair of pad members at a positionbelow the die slot openings of the T dies of the multiple T die; holdinga portion of the intermediate molten multilayer including an upstreamend portion to be cut between the pair of pad members; and shearing theintermediate molten multilayer with the cutting means while themultilayer is held between the pair of pad members.
 16. The moldedmultilayer article manufacturing method according to claim 14 or 15,wherein air is blown from within the bodies of pad members against theintermediate molten multilayer to facilitate the separation from the padmembers on completion of cutting the intermediate multilayer.
 17. Themolded multilayer article manufacturing method according to claim 13,wherein a cutting process comprises the steps of: extending a metal wirein a plane intersecting a plane including the intermediate moltenmultilayer so as to be able to be brought into contact with end surfacesof the T dies of the multiple T die in which the die openings of the Tdies open; and moving the metal wire along the end surfaces of the Tdies along the width of the intermediate molten multilayer.
 18. Themolded multilayer article manufacturing method according to claim 17,wherein a moving operation for moving the metal wire accompanies byheating the metal wire, and taking up a length of the metal wire. 19.The molded multilayer article manufacturing method according to claim13, wherein a cutting operation for cutting the intermediate moltenmultilayer comprises the steps of: disposing a plurality of cuttingmembers in a plane intersecting the intermediate molten multilayer so asto be able to be brought into contact with the exit of the slot openingof the T dies of the multiple T die; and reciprocating the cuttingmembers along the exit of the slot opening of the T dies in directionsparallel to the width of the multilayer sheet.
 20. The molded multilayerarticle manufacturing method according to claim 19, wherein areciprocating operation for reciprocating the cutting members comprises:holding the cutting members in sliding contact with the exit of the slotopening of the T dies and moving the cutting members for a cuttingstroke along the width of the intermediate multilayer to cut it off; andmoving the cutting members for a return stroke to their initialpositions while separating the cutting members from the exit of the slotopening of the T dies.
 21. The molded multilayer article manufacturingmethod according to claim 2, wherein the intermediate molten multilayercomprises a first monolayer sheet of a molten plastics serving as a skinlayer, a second monolayer sheet of a molten plastics serving as a baselayer, and at least one third monolayer sheet of an unfoamed moltenplastics containing a foaming agent, serving as a mid-layer sandwichedbetween the skin layer and the base layer; and said compression moldingprocess comprises the steps of: compressing the intermediate moltenmultilayer in the compression mold, heating the compression mold to makethe mid-layer produce foams, cooling the compression mold, and openingthe compression mold and taking out a molded multilayer article from thecompression mold.
 22. The molded multilayer article manufacturing methodaccording to claim 21, wherein the compression molding process furthercomprises the steps of: replacing the compression mold with anothercompression mold in which the intermediate multilayer is putted beforeheating the former, compressing the latter mold to shape theintermediate multilayer into a molded multilayer article.
 23. A methodfor manufacturing a molded multilayer article by molding a multilayersheet consisting a plurality of polymer layers, said method comprisingthe steps of: extruding a plurality of monolayers of molten polymers byforcing the molten polymers into a multiple T die combined with aplurality of T dies so that the molten polymers are extrudedrespectively through the T dies; passing the monolayers extruded throughthe T dies through a space between a pair of nip rollers disposedopposite to each other; forming an intermediate molten multilayer bysuperposing and laminating the monolayers outside the multiple T die bypressing the monolayers between the pair of rotating nip rollers whilethe polymers are in a molten state or a semi-molten state; advancing thepair of nip rollers together with the multiple T die into a spacebetween an open top half mold and a bottom half mold of a compressionmold while a laminating operation of the pair of nip rollers iscontinued; fixing a front end portion of the intermediate multilayer toone end of the bottom half mold of the compression mold; moving the pairof nip rollers together with the multiple T die backward while alaminating operation of the pair of nip rollers is continued; stoppingthe rotation of the pair of nip rollers and stopping the extrusion ofthe molten polymers while the pair of nip rollers are moved continuouslybackward in order to cut the intermediate molten multilayer; and moldingthe intermediate molten multilayer molding in the compression mold intoa multilayer article of a desired shape.
 24. An apparatus formanufacturing a molded multilayer article by molding a multilayer sheet,said apparatus comprising: a plastication means for separatelyplasticating polymers for forming each of monolayers, and feeding moltenpolymers by pressure; a multiple T die combined with a plurality of Tdies for extruding the monolayers and jointed to the plastication means;moving means for moving the plastication means and the multiple T dieall together; a laminating means provided with the multiple T die toform a intermediate molten multilayer by superposing and laminating themonolayers extruded in molten or semi-molten state; a cutting meansprovided with the multiple T die for cutting the intermediate moltenmultilayer in a predetermined length; and a compression molding meansprovided with a mold for molding the intermediate molten multilayer intoa finished multilayer article of a desired shape.
 25. The moldedmultilayer article manufacturing apparatus according to claim 24,wherein the plastication means are injection units included in aninjection molding machine.
 26. The molded multilayer articlemanufacturing apparatus according to claim 24, wherein the plasticationmeans are extrusion units of an extruder.
 27. The molded multilayerarticle manufacturing apparatus according to claim 24, wherein each ofthe T dies of the multiple T die is provided with a die slot openingadjusting means for adjusting the die slot opening to adjust the widthof the monolayer to be extruded therethrough.
 28. The molded multilayerarticle manufacturing apparatus according to claim 27, wherein the dieslot opening length adjusting means comprises: a pair of decidesdisposed opposite to each other at the die slot opening of each of the Tdies of the multiple T die so as to be movable toward and away from eachother to adjust the length of the die slot opening; servomotors fordriving the pair of decides for axial movement; and ball screwmechanisms for converting output torques of the servomotors intolongitudinal forces and transmitting the linear forces to the pair ofdeckles.
 29. The molded multilayer article manufacturing apparatusaccording to claim 28 further comprising: a data setting means forsetting patterns regarding respective desired shapes for each of themonolayers of the multilayer article; and a control means forcontrolling the respective positions of the decides fitted on each T dieto adjust the width of the monolayer extruded through the same T die onthe basis of the data about the pattern of the shape of the samemonolayer so that the same monolayer is formed in the desired shape. 30.The molded multilayer article manufacturing apparatus according to claim29, wherein the control means executes an open-loop control operation.31. The molded multilayer article manufacturing apparatus according toclaim 30, wherein the control means comprises: an arithmetic means forcalculating position commands specifying respective positions of thedeckles on the basis of the data about the patterns of the respectivedesired shapes of the monolayer; and a controller for controlling theservomotors according to the position commands specifying positions ofthe deckles received from the arithmetic means.
 32. The moldedmultilayer article manufacturing apparatus according to claim 29,wherein the control means executes a closed-loop control operation. 33.The molded multilayer article manufacturing apparatus according to claim32, wherein the control means comprises: an arithmetic means forcalculating position commands specifying positions of the deckles on thebasis of the data about the patterns of the predetermined shapes set bythe data setting means; a sensing means for detecting the respectivepositions of the deckles; and a controller for comparing position feedback signals indicating the respective positions of the deckles with theposition commands and controlling the servomotors so that deviations ofthe deckle position signals from the position commands are reduced tozero.
 34. The molded multilayer article manufacturing apparatusaccording to claim 29 further comprising a sequential control means forthe sequential control of the plastication means, the die slot openingadjusting means, the cutting means, the laminating means, the movingmeans and the compression molding means on the basis of the patterns ofthe predetermined shape of monolayers of the multilayer article.
 35. Themolded multilayer article manufacturing apparatus according to claim 24,wherein the T dies of the multiple T die are so arranged that a thickestmonolayer as the most below layer of the intermediate molten multilayeris extruded.
 36. The molded multilayer article manufacturing apparatusaccording to claim 35, wherein the plastication means jointed to the Tdie through which the thickest monolayer is extruded is connected to theshortest passage among those connecting the plastication means to the Tdies.
 37. The molded multilayer article manufacturing apparatusaccording to claim 24, wherein the laminating means comprises: a pair ofnip rollers for forming a intermediate multilayer by superposing andpressing a plurality of monolayers extruded through the T dies,assembled integrally with the multiple T die so as to lie below the dieslot openings of the T dies of the multiple T die; driving means fordriving the pair of nip rollers for rotation; and actuators for movingthe pair of nip rollers to press the nip rollers against theintermediate multilayers and to separate the same from the intermediatemultilayers.
 38. The molded multilayer article manufacturing apparatusaccording to claim 37, wherein the laminating means further comprises atemperature regulating means for keeping the surfaces of the pair of niprollers at a predetermined temperature.
 39. The molded multilayerarticle manufacturing apparatus according to claim 37, wherein thelaminating means further comprises scrapers for scraping off polymersadherent to the surfaces of the pair of nip rollers.
 40. The moldedmultilayer article manufacturing apparatus according to claim 24,wherein the moving means comprises: a base provided with theplastication means and the multiple T die and mounted movably on a bed;and a means for moving the base between a standby position correspondingto a position where the multiple T die is held on standby, and a workingposition where the multiple T die advances into a space confined by aopen top half mold and a bottom half mold of the compression mold inorder to deliver the intermediate multilayer onto the bottom half mold.41. The molded multilayer article manufacturing apparatus according toclaim 24, wherein the cutting means is disposed integrally with themultiple T die, and is provided with a cutting member for cutting theintermediate molten multilayer at a position below the die slot openingsof the T dies of the multiple T die.
 42. The molded multilayer articlemanufacturing apparatus according to claim 41, wherein the cutting meanscomprises: a pair of pad members for holding the intermediate moltenmultilayer therebetween; a cutting member housed in one of the pair ofpad members so as to be projected from the pad member toward theintermediate molten multilayer to cut it off along a line parallel tothe width of the same; a cooling means for cooling a portion of theintermediate molten multilayer in contact with the pair of the padmembers; actuators for pressing the pair of pad members against theintermediate molten multilayer and moving the same apart from it; and acutter moving means for moving the cutting member along the width of theintermediate molten multilayer.
 43. The multilayer article manufacturingapparatus according to claim 41, wherein the cutting means comprises: apair of pad members for holding the intermediate molten multilayertherebetween; a cutting member housed in one of the pair of pad membersso as to be projected from the pad member toward the intermediate moltenmultilayer to cut it off along a line parallel to the width of the same;actuators for pressing the pad members against the intermediate moltenmultilayer and moving the same apart from it; a heating means forheating the cutting member; and a cutter operating means for projectingthe cutting member from a surface of the pad member.
 44. The moldedmultilayer article manufacturing apparatus according to claim 42,wherein the pad members are internally provided with blowing means toblow air from inside thereof against the intermediate molten multilayer.45. The molded multilayer article manufacturing apparatus according toclaim 44, wherein the cutting member is a metal thin plate or a metalwire.
 46. The molded multilayer article manufacturing apparatusaccording to claim 41, wherein the cutting means comprises: a metal wirefor cutting the intermediate molten multilayer; a wire extending meansfor extending the metal wire in a plane intersecting a plane includingthe intermediate molten multilayer so that the metal wire can be broughtinto contact with an exit of a slot opening of the respective T dies ofthe multiple T die open; and a means for moving the wire extending meansto move the metal wire along the exit of the slot opening of the T diesof the multiple T die.
 47. The molded multilayer article manufacturingapparatus according to claim 46, wherein the cutting means furthercomprises: a heating means for heating the metal wire; a feed reel forfeeding the metal wire; and a take-up reel for taking up the metal wire.48. The molded multilayer article manufacturing apparatus according toclaim 46, wherein the metal wire is substituted by a metal thin platebent so as to be able to be brought into contact with the exit of theslot opening of the T dies of the multiple T die.
 49. The moldedmultilayer article manufacturing apparatus according to claim 41,wherein the cutting means comprises: a cutting members for cutting theintermediate molten multilayer; a support means for supporting thecutting means rollably so as to bring the cutting members of the cuttinghead into contact with the exit of the slot opening of the T dies of themultiple T die; a moving means for moving the support means to move thecutting members along the exit of the slot opening of the T dies; aguide means for guiding the support means for movement; and a means foroperating the cutting members so that the cutting members are kept incontact with the exit of the slot opening of the T dies while thecutting members are being moved for a cutting stroke to cut theintermediate molten multilayer, and the cutting members are kept apartfrom the exit of the slot opening of the T dies while the cuttingmembers are being moved to its standby position for a return stroke. 50.The molded multilayer article manufacturing apparatus according to claim49, wherein the means for operating the cutting means comprises: a guidepin attached to one end of the support means; a cam follower attached toone end of the swinging support means; and an eccentric guide barextended in parallel to the guide means, and provided with a cam grooveto control the cam follower so that the cutting members are brought intocontact with and kept apart from the exit of the slot opening of the Tdies of the multiple T die.
 51. The molded multilayer articlemanufacturing apparatus according to claim 24, wherein the compressionmolding means further comprises: a mold clamping means for opening,closing the mold and clamping the closed mold; a mold heating means forheating the mold to make the unfoamed polymer foam; and a mold coolingmeans for cooling the mold.
 52. The molded multilayer articlemanufacturing apparatus according to claim 51, wherein the compressionmolding means further comprises a mold changing means for changing themold for another one.
 53. The molded multilayer article manufacturingapparatus according to claim 52, wherein the compression molding meansfurther comprises a fixing means for fixing a front end portion of theintermediate molten multilayer onto the mold.